(a) Field of the Invention
The present invention relates to an improved stricture of a depress-type safety switch, and in particular, a simple and easy-installed automatic safety switch being employed in the socket of an extension wire.
(b) Description of the Prior Art
Conventional safety switches are widely available in the market, and some of these switches have very complicated structure and are complicated in manufacturing and installation. Therefore, these increase the production cost. It is not economical if these switches are used in socket for the commonly available extension wire. There is a commonly found extension wire with a set of insertion holes associated with an individual switch. As a result, the cost of this extension wire is high and it is also not economically to be employed in the extension wire.
Accordingly, it is an object of the inventor to provide an improved structure of a depress-type safety switch, which can eliminate the above-mentioned drawbacks.
Accordingly, it is an object of the present invention to provide an improved structure of a depressive safety switch comprising a main body, press button, actuating block, wherein the top section of the main body is opened to accommodate the press button and the actuating block, and the bottom panel is provided with a left, a center and a right terminal for connection to a socket and a power source wire. The interior of the actuating block is provided with a main spring, and the safety switch is characterized in that the right side of the actuating block is a top section with a positioning slot having a V-shaped engaging block, and the right terminal is connected upward to a bi-metallic engaging plate made from two metals of different properties, and the top end of the engaging plate is a fastening peg extended to the positioning slot of the actuating block, thereby the depression of the press button allows the fastening of a fastening peg at the bi-metallic engaging plate with the engaging block to form a closed circuit, and if the current exceeds a predetermined value or a short circuit occurs, heat is transferred from the right terminal to the bi-metallic engaging plate and is moved toward the right so that the fastening peg is disengaged from the fastener, and the press button is restored to its original position by the main spring to form an opened circuit.
The foregoing object and summary provide only a brief introduction to the preset invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.